1. Field of the Invention
The present invention relates to the field of storage of electronic data. More particularly, the present invention relates to the compression and decompression of data stored to a portable memory device.
2. Background of the Invention
Portable memory devices, sometimes referred to as “key chain” memory devices or Thumbdrives™ (which is a trademark of the assignee of the present invention), are small portable data storage devices. These devices have become a class of indispensable computer peripherals that are widely utilized in business, educational and home computing. These devices are very small in comparison with other data storage devices such as personal computers (PCs), personal digital assistants (PDAs), magnetic disks, or compact disks (CDs). Indeed, the name “keychain” memory device describes the devices as similar in size to a key. Portable memory devices are generally not permanently fitted to a particular host platform, such as a PC. Rather, they can be conveniently attached to and removed from any computer having the appropriate connection port (e.g., a serial bus port like a USB port, or IEEE 1394 port (“Firewire”)). Thus, these portable data storage devices enable a user to transfer data among different computers that are not otherwise connected. Because these devices utilize a non-volatile solid-state memory (e.g., flash memory) as the storage medium, they do not require moving parts or a mechanical drive mechanism for accessing data. The absence of a drive mechanism enables portable data storage devices to be more compact than surface storage devices such as magnetic disks and CDs. Also, because there are no moving parts, reading and writing to the memory can be done much more rapidly than to magnetic disks and CDs. Portable data storage devices also have a much higher memory capacity than magnetic disks, holding up to 256 megabytes, as compared to 1.4 megabytes for magnetic disks.
Although storing data to a portable memory device has proven useful, the utility of these devices is limited by their inability to store larger quantities of data without increasing their size.